This is a program of interdependent, mutually-reinforcing projects in the epidemiology of cancer. We plan to conduct analyses of substantial sets of data already collected and to collect new data, using both case-control and prospective study designs. Diet will be a prime focus, but we will also study other factors hypothesized to be related to the epidemiology of all the sites of interest. Project 1 will analyze data already collected from a case-control study of Erie, Niagara and Monroe Counties, examining diet and other factors in gastric, esophageal and laryngeal cancer. Project 2 will gather data from the same counties for studies of cancer of the cervix, breast, ovary, endometrium, prostate and pancreas. Serological studies of nutrients and antibodies to viruses will be carried out as part of this inquiry. Project 3 will study the incidence of cancer at many sites among individuals who exhibited various dietary patterns in 1980 in a cohort of 58,000 residents of New York State.